File-by-File patching shrinks the size of Android app updates, resulting in data savings4
But Google's software engineers have improved upon this with a new system called File-by-File patching. Using this technique, the size of an app update could shrink 65% to as much as 90%. As a result, less data is consumed while updating. Of course, using a Wi-Fi network would save all of your data, but most users don't take the time to make sure that they have a Wi-Fi connection before updating a few apps from the Play Store.
According to Google, using File-by-File patching will save 6 petabytes of user data each day. Considering that each petabyte is equivalent to a million GB, we're talking about saving some serious amounts of data here. Take a look at the chart that accompanies this story, and you can get a feel for the amount of data you're saving. For example, with a recent update to Google Maps the file size was 32.7MB. Using the bsdiff algorithm reduced the size by 46% to 17.5MB. Using File-by-File patching resulted in a savings of 71% from the original file to 9.6MB.
File-by-File patching is open source, so if you're interested in making contributions to reducing file sizes by a larger amount, click on this link.